Mayo Clinic researchers develop blood test to track aggressive brain cancer progression

UAE—Mayo Clinic researchers have discovered a promising new method to monitor high-grade gliomas, among the most aggressive forms of brain cancer.

Their feasibility study demonstrates that a personalized blood test, customized to each patient’s unique tumor DNA, could offer a faster and less invasive alternative for tracking cancer progression.

Doctors currently depend on imaging scans and surgical biopsies to monitor gliomas, yet both approaches present significant challenges.

Scans frequently struggle to differentiate between actual tumor growth and treatment-related effects like inflammation.

Meanwhile, biopsies require invasive surgical procedures, making them unsuitable for regular monitoring.

The new approach, published in Clinical Cancer Research, may equip clinicians with an additional tool to track tumor changes over time and modify treatment strategies accordingly.

The research team focused on tumor DNA fragments that circulate in the bloodstream.

When glioma cells die during tumor growth, they release pieces of their DNA into the blood, creating genetic markers specific to each individual tumor.

Detecting these markers proves particularly difficult with gliomas because the blood-brain barrier, a natural protective mechanism, prevents many substances from leaving the brain.

Consequently, gliomas release fewer DNA fragments into the bloodstream compared to other cancers.

Researchers addressed this obstacle by targeting DNA junctions, a specific type of tumor DNA fragment that exists in higher quantities.

This strategy enhanced their detection sensitivity, allowing them to identify even minimal signs of tumor progression.

DNA junctions form when tumor genetic material breaks and rearranges, unlike normal DNA that follows an organized sequence.

The study revealed that these amplified DNA junctions, due to their greater abundance, may deliver a clearer understanding of how the disease progresses.

Dr. George Vasmatzis, who leads the research as co-director of the Biomarker Discovery Program at Mayo Clinic’s Center for Individualized Medicine and Comprehensive Cancer Center, explains that this work builds on years of studying genetic rearrangements.

 The findings open new possibilities for patient-specific monitoring and targeted interventions.

The research team analyzed samples from patients with high-grade gliomas using whole genome sequencing to map each tumor’s unique genetic blueprint.

They identified patient-specific DNA junctions and then developed personalized blood tests to detect these genetic markers in plasma samples.

The test successfully detected tumor DNA in approximately 93% of cases where these DNA junctions were present.

Notably, some patients showed rising tumor DNA levels in their blood before MRI scans revealed any changes, suggesting the test could provide early warning signals for disease progression.

Dr. Terry Burns, a neurosurgeon at Mayo Clinic in Rochester, Minnesota, and study co-author, emphasizes that tracking each tumor’s distinct molecular signature aims to shift from reactive to proactive treatment approaches.

This research could establish the foundation for tools that enable clinicians to make well-informed treatment decisions as early as possible.

The team plans future studies to evaluate how effectively blood-based tumor tracking correlates with glioma progression across larger patient populations.